Dave gave you a really good rundown on some of the basics regarding your question and as weldwade added, knowing which wire, diameter, and a few other details would help with additional information and actual "mean" settings.
I am making an "assumption" here, that being, that your SA 200 is CC only and not equipped for CV output. You can run self-shielded flux cored wires on it, but you'll have a much more difficult time dialing the performance of the wire in and if you are doing any sort of code type work you will need to qualify the weld procedure as there are not pre-qualified ones available. Solid wires in short-circuiting transfer that are done with a CC driven voltage sensing feeder will not yield desirable results due to an incompatable volt/amp curve to properly drive the LN-25 and provide the correct volt/amp output for the solid wires when they are to be operated in short-circuiting parameters. ESAB has some really good information to explain this further and it is very straight-forward and easily understandable. I have attached the link below.
Good luck and best regards, Allan
http://www.esabna.com/us/en/newsletters/Using-Cored-Wires-with-Voltage-Sensing-Wire-Feeders.cfm